Feeding interval and postprandial intestinal blood flow in premature infants

Abstract

The feeding interval is an important factor in enteral feeding of premature infants. We investigated postprandial intestinal blood flow in stable very-low-birthweight infants fed at 2-h and 3-h intervals. We used pulsed wave Doppler ultrasound to measure blood flow velocity of the superior mesenteric artery (SMA) before feeding and at 15, 30, 45, and 60 min after feeding. Measurements were made on the day of starting enteral nutrition (1 or 2 days of age), and at 3 and 5 days of age. A total of 21 studies were performed in seven infants fed every 2 h, and 54 studies were performed in 18 infants fed every 3 h. In infants fed every 2 h, SMA blood flow velocity increased from before feeding to 30 min after feeding and then decreased at 60 min after feeding. In infants fed every 3 h, SMA blood flow velocity increased after feeding, reaching a peak at 30 min. The correlation coefficients between the volume of milk per feed and the postprandial increase in time-averaged mean blood flow velocity were 0.398 (P = 0.074, n = 21) and 0.597 (P = 0.000, n = 54) in infants fed at 2-h and 3-h intervals, respectively. SMA blood flow velocity significantly increased after feeding in infants fed at 2-h and 3-h intervals. The volume of milk per feed might affect the postprandial increase in SMA blood flow velocity.